For many medical reasons it is necessary or desirable to administer various medicaments to body cavities. In order to provide a simple method of applying the medicament with a minimum of discomfort, the medicaments are often administered with a syringe type applicator. A patient may self administer the medication by use of a syringe prefilled with the prescribed medicament at the desired dosage level.
An applicator of this type is disclosed in European Patent Application No. 6545. This applicator consists of an expandable cannula provided with a longitudinal cylindrical hollow chamber. The chamber contains a metered quantity of a substance to be administered to a patient. Both ends of the chamber are provided with easily removable sealing means. A rod provided with a grip at one end and with a piston conveniently fitting the hollow chamber of the cannula at the other end is arranged such that by pushing the rod into the hollow chamber all the substance contained therein is ejected. This syringe type applicator is intended for single use and has a relatively simple form. However, it is comprised of several parts which complicates its process of manufacture. Manufacturing costs of disposable applicators are of critical importance for such devices. The applicator disclosed by European Pat. No. 6545 would be undesirably expensive to manufacture.
A conventionally used applicator for administering medicaments into body cavities is disclosed in Danish Pat. No. 134,308. This applicator comprises a flat container section and a metering chamber, in the form of a cannula, which can be inserted into, e.g. the nostril. When pressure is applied to the container section the drug is ejected through the cannula. The pressure is applied by the fingers of the user.
The type of applicator disclosed by Danish Pat. No. 134,308 has been well accepted and works well in many cases. A general problem with it is, however, dosing accuracy. In order to obtain dosing accuracy, which is of critical importance for some types of drugs, the drug composition included in the container must have low viscosity. In order to obtain approximately the correct dose of high viscosity compositions, a large excess of the drug composition must be filled into the container. It is, however, generally not accepted by the health authorities that single dose containers have more than a slight excess of the active drug.
The ideal situation to be achieved in a disposable applicator is, of course, that it should contain only a single dose which corresponds exactly in amount to the dose that shall be administered. It is thus obvious that the type of applicator disclosed by Danish Pat. No. 134,308 is not well suited to administering high viscosity composition. When low viscosity compositions are administered through an applicator of this type, the problems are less, but even then are not totally avoided.
This invention provides a disposable single dose of the Invention syringe type applicator for applying medicaments to body cavities.
The disposable single dose syringe type applicator of the present invention is an elongated body which comprises two integrally joined sections which can be separated by breaking. One is a barrel, a hollow tubular section, which constitutes a medicament reservoir having two openings. The other section is a plunger which, prior to separation from the medicament reservoir section, seals one opening of the reservoir. The reservoir is filled with medicament from the other opening end thereof after which such opening end of the medicament reservoir is provided with an easily removable sealing means. After separation, the rod-like plunger section slidably fits into the barrel, or reservoir, in such a way that essentially the whole medicament content of the reservoir is ejected therefrom when the plunger is inserted into the reservoir.
The syringe applicator of this invention can be easily and inexpensively manufactured in one piece. The disclosed applicator has a high dosing accuracy and can be used for various types of medicament compositions. The applicator of the invention delivers essentially the whole amount of medicament with which it is prefilled.